Variable grind feed mill



Feb. 14, 1956 w. w. DRAvr-:s 2,734,687

VARIABLE GRIND FEED MILL Filed OO'L. l, 1952 2 Sheets-Sheet 1 @rrowsxs United States Patent VARIABLE GRIN!) FEED MILL William W. Draves, Minneapolis, Minn.

Application October 1, 1952, Serial No. 312,534

9 Claims. (Cl. 241-186) My invention relates to improvements in a feed grinding mill. In particular it relates to a feed mill which provides a selection of the grade of grind.

It is desirable in a feed grinding mill to have a variable output as to the coarseness or neness of the product ground. Prior to my invention the grade of grind was principally varied by removing the entire screen of the mill and replacing it with a screen of a different mesh. Changing the grade of grind therefore took a considerable amount of time and labor. Although one means of changing the grade of grind in a hammer mill was to provide a rotatable screen having segments of different mesh wherein the screen was rotated to an operating position, this has not proved entirely satisfactory.

My invention provides an easier, a quicker and more workable method for varying the grade of grind than any yet developed in the prior art. It will prove invaluable in saving time and labor, and hence operating costs, when grinding load after load of feed where each load must be of a different grind. Briey, I provide a feed grinding mill having fixed arcual sections of screen, each section of screen having a different size of mesh than the others, individual ducts lead from each section of screen to a sleeve type valve, the sleeve of the valve having apertures for receiving the open end of each of these .ducts and the inner member of the valve having a single aperture, which will cooperate with one of the apertures in the sleeve of the valve at a time to form a passageway leading from one section of screen to a blower which is connected to the inner chamber of the valve.

- Although my invention has been illustrated as applied t a hammer mill, it need not be limited to this for it is equally useful and applicable in any type of feed grinding mill.

It is an object of the present invention to provide an improved feed grinding mill.

It is another object of the present invention to provide a feed grinding mill which gives a selection of the grade ofpgrind by means of a sleeve type valve having a plurality of apertures in the sleeve of the valve and a single aperture in the inner member of the valve, a blower connected to the inner member of the valve, a means for grinding different grades of grind, and ducts leading from said means to the apertures in the sleeve of the valve.

It is another object of the present invention to provide a hammer type feed grinding mill having revolvable hammers which force the feed through fixed arcual sections of screen, each section of screen having a different size of mesh than the others, individual ducts leading from each section of screen to a single outlet, and means operative upon said ducts to provide a suction in only one duct at a time.

It is a further object of the present invention to provide a hammer type feed grinding mill improved over other hammer mills in that the screening is formed in separate arcual sections, each section being xed and having an individual size of perforations, separate ducts lead from each individual section of screen to a juncture at a 2,734,687 Patented Fels. 14, 1956 sleeve type valve having apertures in the sleeve to receive the open ends of the ducts and a revolvable inner member having only one aperture which cooperates with only one of the apertures in the sleeve at a time, together with a passageway leading from the inner member of the valve to and through a blower and into bins or other suitable receptacles.

These and other objects will be disclosed in the course of the following specification and claims, reference being had to the accompanying drawings wherein:

Fig. 1 is a side elevation of the associated parts of my new and improved mill.

Fig. 2 is a section taken along line 2 2 of Fig. l showing the front of the housing of the mill and the ducts leading from this housing to the juncture at the valve.

Fig. 3 is a section taken along line 3 3 of Fig. 2 showing the sleeve type valve.

Fig. 4 is a section taken along line 4 4 of Fig. l showing the interior of the feed grinding means.

Fig. 5 is a section taken through the center of the housing showing a side view of the feed grinding means.

Fig. 6 is a detail View taken along line 6 6 of Fig. 4 showing the means for supporting the semi-circular section of screen.

Fig. 7 is a detail view taken along line 7 7 of Fig. 4 showing the abutment supporting the other two arcual sections of screen.

I Referring now to the drawings, general reference numeral 10, Fig. 1, indicates a hammer mill, one part of which is the housing 12. This housing contains the feed grinding means and is comprised of a cast casing 14 having an apertured front wall 16 and a rear wall 18. The casing is supported on a base 20. Referring in particular to Figs. 4 and 5, it is seen that the side walls and the top of the casing 14 are principally open, and most of this area will be closed by doors subsequently explained. The side walls of the casing 14 are open except for side portions 22 and 24, Fig. 4, which extend from the base 20 to extremities 26 and 28 respectively not quite midway of the height of the housing 12. The top of the casing 14 is formed of a horizontal projection 30, Fig. 5, of the front wall 16, a horizontal projection 32 of the rear wall 18, and support members 34 and 36, Fig. 4, which extend the length of the housing 12 between projections 30 and 32. Support members 34 and 36 together with a portion of each of the horizontal projections 30 and 32 form an opening 38 and also form a support for a feed hopper 40. A vertical extension 42 of the support member 34 projects into the housing 12 and forms one wall of a passageway V44. Similarly a vertical extension 46 of the support member 36 projects into the housing 12 and forms a second wall of the passageway 44.

Formed in the front wall 16 of the casing 14 is a recessed abutment 50, Fig. 5, which has a central aperture 52. Rear wall 18 has a recessed abutment 54 through which passes a central aperture 56. Held within the aperture 52 by the abutment 50 is a shaft bearing v58 for the shaft 60, and similarly the abutment 54 in the rear wall 18 supports a second shaft bearing 62 within the aperture 56. Shaft bearings 58 and 62 support the shaft 60 for rotation relative to the housing 12. The shaft 60 is rotated by means of a motor 64, Fig. l, located apart from the housing 12 and mounted on a pedestal 65. The driving shaft 66 of the motor v,64 is connected to the shaft 60 by means of a coupling 68. The coupling 68 consists of a piece 70 secured to the shaft 60 and a similar piece 72 secured to the shaft `66, and these two pieces are bolted together. Referring back to Figs. 4 and 5, the hammers 74 vof the hammer mill are secured to the shaft 60 for rotation. The hammers 74 are carried by two rows of rectangular spacers 76, one row of spacers being perpendicular to the other. These spacers are secured to a plurality of sleeves 78, which are in turn secured to the shaft 60.

The hammers 74 of the hammer mill are adapted to rotate within an inner chamber 80, Fig. 4, of the housing 12. This chamber is cylindrically formed by arcual sections of screen 82, 84 and 86. Each of the sections of screen 82, 84 and 86 have an individual size of perforations, that is they each have a different sized mesh from that of the other two screens. The semiacircular section of screen 86 usually is a line meshed screen and the other two sections of screen generally have a coarse and a medium mesh respectively.

The section of screen S2 acts as a partition between the inner chamber Si) and an outer chamber 88 formed in the housing 12. The screen 82 is removably secured to arc-shaped abutments 90 formed on both the front wall 16 and the rear wall 18. Similarly, arc-shaped abutments 92 are formed on the front wall 16 and rear wall 18 to support the arcual section of screen 84, which acts as a partition between the inner chamber 80 and a second outer chamber 94. The semi-circular section of screen 86 acts as a partition between inner member 90 and a third outer chamber 96. Screen 86 is supported by means of a screen support 98 which merely holds ther screen against semi-circular abutments 100, which are formed on both the front wall 16 and the rear wall 1S of the casing 14. It must be recognized that the disclosure of Fig. 4 illustrates the abutments 90, 92 and 160 formed in the rear wall 1S of the casing 14 and that similar abutments are formed in the front wall 16. These abutments are shown in detail in Fig. 7.

A simple means for changing the screen 86 is provided by the method of holding the screen support 98 in position. A door 102 hinged to the extremity 26 of the side portion 22 gives entrance into the chamber 96 from one side of the housing 12 and a similar door 104 hinged to the extremity 2S gives entrance into the chamber 96 from the other side of the housing 12. The two doors 102 and 164 each have a slotted horizontal portion 166 and 168, respectively. A pair of screen support holding members 110 engage two slots 111 in each of the horizontal portions 106 and 108. Referring to the detail of Fig. 6, these screen support holding members 110 consist of a rod 112 having at one extremity an enlarged hollow cylindrical portion 114 and at the other extremity a threaded end 116. The hollow cylindrical portions 114 encircle a transverse rod 118, which together with other rods form a part of the screen support 98. Internally threaded members 120 screw over the threaded ends 116 of the rods 112 and form a means to hold the rods 112 within the slots 111 so that the screen support 9S may hold the screen 86 against the semi-circular abutments 100. A handle 121 extends between the pair of screen support holding members 110 on each side of the housing 12 and facilitates lifting the screen support 98 into position.

The horizontal portion 106, Fig. 4, of the door 102 forms a partition between the chamber 96 and chamber 88, and also forms a part of the frame for a door 122, which provides an entrance into the chamber 88. Similarly the horizontal portion 108 of the door 184 forms a partition between the chamber 94 and the chamber 96, and also forms a part of the frame for a door 124, which provides an entrance into the chamber 94. Hinges 125 secure the top of the doors 122 and 124 to support members 34 and 36, respectively, to hold the doors in position. However, these doors may be held in position by any suitable means. Doors 122 and 124 form a means for getting at the screens 82 and 84, respectively, should the latter need any repair or if it is desired to change these screens.

I have provided a means, which is an important feature of the present invention, for carrying the feed away .from the separate fixed arcual sections of screen to collection bins. Formed within the chambers 88, 94 and 96, Fig. `4, are duct members 126, 128, and 130, re-

spectively. Duets 126 and 128 at the top have a ange portion 129 which is bolted to the vertical extensions 42 and 46, respectively. The duct members 126, 128 and 13G, which are removable, surround their respective sections of screen 82, 84 and 86 and lead to apertures 132, 134 and 136, Fig. 2, formed in the front wall 16 of the casing 14. Duct member 126 leads to the aperture 132 where it joins with a cylindrical duct 138. Similarly duct member 128 joins a duct 140 and duct member 13) joins with a duct 142. Duets 138, 14@ and 142, Fig. 2, lead from the apertures 132, 134 and 136 respectively to a sleeve type valve 15G located exterior to the housing 12.

Referring to Fig. 3, thev valve 156 is comprised of sleeve 152 having a portion 154, whose internal surface 156 is cylindrical and whose exterior surface 158, which may be either cylindrical or many sided, has apertures 166, 162 and 164, Figs. 1 and 3, which extend to the internal surface 156 and receive the ends of the ducts 138, 146 and 142, respectively. An inner member 166 of the valve 156 is litted within the sleeve 152 for rotation adjacent the sleeve portion 154. This mem ber, which is cylindrically shaped, is hollow and is provided with a single aperture 16S. The aperture 168 is of the same size and shape as the apertures 160, 162 and 164, which are formed in the sleeve portion 154, and is adapted to cooperate with these apertures. An end plate 176 of the valve 150 is secured to an extension 172 of the sleeve 152 and forms a groove 174 in which rotates a periphery 176 of an end wall 178 of the inner member 166. Wall 178 of the inner member 166 has a centrally located aperture 186 through which passes the threaded portion of a shaft 182. Shaft 182 has a machined enlarged portion 184, which is adapted to rotate in a central aperture 186 in the end plate 170. The enlarged portion 134 is of a greater diameter than the aperture 180, and the shaft 182 is secured to the end wall 178 of the member 166 by means of a nut 188. Secured to the shaft 182 at its other extremity s a sprocket wheel 19t). Sprocket 196 coacts with a chain drive 191 for rotating shaft 182 and in conjunction with it to revolve the inner member 166 of the valve 150 from a distance. This permits operation of the valve 150 from the floor above, if such is desired. A cylindrical extension 192 of the sleeve member 152 leads from the interior of the inner member 166 to a blower 194, Fig. 1. The blower 194 is motivated by a motor 196, supported on a pedestal 198. The discharge end of the blower 194 connects to a duct 266 which leads to feed collectors, not illustrated.

Located in the rear wall 1S of the casing 14 is a weighted door 202, Fig. 4, which is normally closed but which is adapted to swing open should there be la lack of air entering the chamber through the opening 38 to feed the suction blower 194.

The operation of my invention is as follows: Assuming the motors 64 and 196 to be operating and the valve 150 to be in the position shown in Fig. 3, suction supplied by the blower 194 will draw air from the chamber 80, Fig. 4, through the section of screen 86. Feed, which is put into the mill through the hopper 40, will be carried by this suction to the section of screen 86 and will be forced by the hammers 74 through this screen. The blower 194, which is drawing air from the chamber 80 through the screen 86, will carry the feed through the duct member and through aperture 136, Fig. 2, in the housing 12 into the duct 142. The feed will then pass through apertures 164 and 168, Fig. 3, into the inner member 166' of the valve 150, and will be drawn through the cylindrical extension 192 into the center of the blower 194 and blown out through the duct 260, Fig. 1, into feed collectors. The suction force of the blower 194 will draw nearly all of the feed put into the mill through the screen 86, however the hammers 74 may force a slight drift of feed through the screens 82 and 84. When it is desired to change the grade of grind inner member 166 is rotated by means of sprocket wheel 190 to the proper position to open the valve 150 into one of the other ducts. Thus, when the aperture 168 is rotated to coincide with aperture 160, suction will be applied only at screen 82; and as there is no suction at screens 84 and 86, all of the feed put into the mill except for a very slight drift forced through theV latter screens will pass through screen 82. Similarly, when the aperture 168 coincides with the aperture 162, suction will be applied at the screen 84 and the feed will then be forced through this screen. The simple means which has been provided for removing screen 86 is operated by merely loosening either the two threaded members 120, Fig. 6, positioned just inside the door 122 or the two threaded members 120 positioned just inside the door 124. For convenience of operation it will be assumed that door 124, Fig. 4, has been opened and that the two threaded members 120 just inside this door have been loosened. This permits opening of the door 104, which when opened causes the screen support holding members 110 along that side to slip out of the slots 111, and consequently one side of the screen support 98 drops down until the support 98 contacts the duct member 130. Screen 86 will then fall away from the abutments 100, and the operator may reach through the door 104 and pull out the semi-circular section of screen. Putting in a new screen merely involves placing the section of screen on the lowered screen support 98 and by means of the handle 121 pulling the screen support holding members 110 up until the screen is tight against the abutments 100. When the operator closes the opened door 104, the screen support holding members 110 will t within the slots 111 and will then hold the screen support in position. Doors 122 and 124 provide an entrance into the interior of the mill so that the operator may hold the screen in position until the door 104 has been closed. The threaded members 120 may then be tightened to secure the door 104 in the closed position. Doors 122 and 124 likewise provide a means to get at the sections of screen 82 and 84, respectively, for repair purposes and if necessary for changing of size of the mesh. It is believed that this need not be further explained in the operation for the description is self-explanatory.

It will be obvious to those skilled in the art that my invention may be modified by many substitutions and equivalents and that this disclosure is intended to be illustrative only. Therefore, I intend to be limited solely by the scope of the appended claims.

I claim:

1. A feed grinding mill comprising grinding means having a variable output as to the grade of grind, ducts leading from said means to a juncture, each of said ducts adapted to transport one specific grade of grind, a single outlet connected to the juncture of said ducts and extending therefrom, a valve positioned at the juncture of said ducts for opening only one of said ducts into said single outlet at a time, and a suction means connected to said single outlet for applying a suction in said ducts.

2. In a feed grinding mill, the combination of fixed arcual sections of screen forming a cylindrically shaped chamber, each section of screen having an individual size of perforations, means carried within said cylindrical chamber for forcing the feed through said sections of screen, a sleeve type valve comprising a revolvable inner member having an open end and having a single aperture in a side thereof and a sleeve surrounding said inner member and having a plurality of apertures, ducts extending from each of the apertures of said sleeve to each of said sections of screen, and a blower connected to the open end of said inner member of said valve whereby a suction may be applied at a selected individual section of screen.

3. In a hammer type feed mill, the combination of a housing, an inner cylindrical compartment formed within said housing, several outer compartments formed within said housing adjacent said inner compartment, xed wallforming screens separating the inner compartment from the outer compartments of said housing, a plurality of revolvable hammers disposed within the inner compartment of said housing, ducts extending from each of said outer comparents through said housing and joining in a single outlet, a suction means connected to said outlet, and means carried by and operative upon said ducts to provide a suction in only one duct at a time.

4. In a hammer type feed mill, the combination of a housing, an inner chamber formed within said housing, several outer chambers formed within said housing adjacent to said inner chamber, fixed screens forming the walls of said inner chamber, each screen being a partition between said inner chamber and one of said outer chambers and having an individual size of perforations, a shaft carried by said housing and extending through said inner chamber, a plurality of revolvable hammers carried by said shaft for rotation within said inner chamber adjacent said screens, ducts formed within each of said outer chambers and leading from each of said screens to a juncture, a single outlet connected to the juncture of said ducts and extending therefrom, and a valve positioned at the juncture of each of said ducts with the outlet for maintaining only one duct open at a time.

5. In a hammer type feed mill, the combination of a housing, an inner chamber formed within said housing, a feed delivery opening in said housing, a passage leading from said opening to a similar opening in said inner chamber, several outer chambers formed within said housing adjacent to said inner chamber, fixed arcual sections of screen forming the walls of said inner chamber, each section of screen forming a partition between said inner chamber and one of said outer chambers and having an individual size of perforations, a driven shaft carried by said housing and extending through said inner chamber, a plurality of hammers carried by said shaft for rotation within said inner chamber adjacent said screens, ducts formed within each of said outer chambers and leading from each of said sections of screen to a juncture, a valve positioned at the juncture of said ducts for maintaining only one duct open at a time, blower means, and a single duct leading from said valve to said blower means whereby a suction may be applied at a selected individual section of screen.

6. In a` hammer type feed mill, the combination of arcual sections of screen forming a Vcylindrically shaped chamber, each section of screen having an individual size of perforation, a driven shaft extending through said chamber, a plurality of hammers carried by said shaft for rotation within said chamber adjacent said screens, ducts leading from each section of screen to a juncture, and a valve positioned at this juncture comprising a sleeve having apertures for receiving the open ends of said ducts and a rotatable inner member surrounded by said sleeve having an open end and having an aperture in a side thereof adjacent said sleeve.

7. In a hammer type feed mill, the combination of a housing, a cylindrically shaped inner chamber formed within said housing, a feed delivery opening in said housing, a passage leading from said opening to a similar opening in said inner chamber, three outer chambers formed within said housing adjacent to said inner chamber, three arcual sections of screen forming the walls of said inner chamber and each having an individual size of perforation which are graded as a tine, medium and a coarse mesh, each section of screen forming a partition between said inner chamber and one of said outer chambers, a shaft carried by said housing and extending through said inner chamber, motor means for rotating said shaft, a plurality of revolvable hammers carried by said shaft for rotation within said inner chamber adjacent said screens to force the feed through said sections of screen, ducts formed within each of said outer chambers and leading from each of said sections of screen to a juncture, a valve positioned at the juncturev of said ducts comprising a sleeve having three apertures for receiving the dpen ends o f vsaid ducts, and a rotatable inner member surrounded by said sleeve having an open end and having an aperture in a side thereof adjacent said sleeve, suction means, and a single duct leading from the open end of said inner member of said valve to said suction means, whereby a suction may be applied at a selected individual section of screen.

8. A feed grinding mill comprising grinding means having a variable output as to the grades of grind, ducts leading from said means to a juncture, each of said ducts adapted to transport one specific grade of grind, a single outlet connected to the juncture of said ducts and extending. therefrom, and a valve connected to said ducts and positionedat the juncture of each of said ducts with the single outlet for maintaining only one duet open at a time.

9. A feed grinding mill comprising grinding means having a variable output as to the grades of grind, ducts leading from said means to a juncture, each of said ducts 8 adapted to transport one speeic grade of grind, and a valve positioned at the juncture of said ducts comprising a sleeve having apertures for receiving the open end of each of said ducts and a rotatable inner Amember surrounded by said sleeve having an open end and a single aperture in a side thereof adjacent said sleeve.

References Cited inthe le of this patent UNITED STATES PATENTS 110,625 Booton Jan. 3, 1871 1,698,758 Knittel Jan. 15, 1929 1,861,471 Frickey June 7, 1932 1,864,920 Masters June 28, 1932 1,879,269 Hutchison Sept. 27, 1932 2,231,814 McNamara Feb. 11, 1941 2,258,537 Calkins Oct. 7, 1941 2,325,101 Bonnafoux July 27, 1943 FOREIGN PATENTS 18,611 Great Britain of 1912 

